Evaluation of the Impact of Body Position on Primary Central Sleep Apnea Syndrome

Objective: To evaluate the impact of the body position on primary central sleep apnea syndrome.

Methods: Fifty-five subjects diagnosed with central sleep apnea (CSA) through polysomnographic examinations were prospectively enrolled in the study. All patients underwent cardiologic and neurologic examinations. Primary positional central sleep apnea (PCSA) was determined when the supine Apnea-Hypopnea Index (AHI) was greater than two times the non-supine AHI. The primary PCSA and non-PCSA groups were compared in terms of demographic characteristics, sleep parameters, and treatment approaches.

Results: Overall, 39 subjects diagnosed with primary CSA were included in the study; 61.5% of the subjects had primary PCSA. There were no differences between the primary PCSA and non-PCSA groups regarding age, sex, body mass index (BMI), co-morbidities, and history of septoplasty. In terms of polysomnography parameters, AHI (P=.001), oxygen desaturation index (P=.002), the time spent under 88% saturation during sleep (P=.003), number of obstructive apnea (P=.011), mixed apnea (P=.009), and central apnea (P=.007) was lower in the primary PCSA group than in the non-PCSA group. Twenty-nine percent of the patients in the primary PCSA group were recommended position treatment and 71% were recommended positive airway pressure (PAP) therapy; all patients in the non-PCSA group were recommended PAP therapy.

Conclusions: Our results demonstrated that the rate of primary PCSA was high (61.5%) and primary PCSA was associated with milder disease severity compared with non-PCSA. The classification of patients with primary CSA regarding positional dependency may be helpful in terms of developing clinical approaches and treatment recommendations.